Argonne National Laboratory has developed a superabsorbing hydrogel-based process for the decontamination of cesium from concrete and other porous building materials (see, e.g., U.S. Pat. No. 7,737,320, which is incorporated herein by reference in its entirety). This process uses commercially available spray technology, commercially available biocompatible polymers, common chemical reagents, and commercial wet-vacuum technology. It works by spraying a water-based chemical on the concrete surface, followed by spraying the surface with a superabsorbing gel. The gel retains its consistency at relatively high temperatures and humidity for many hours. The gel is removed by wet-vacuum technology, and the recovered gel material can be dehydrated to significantly reduce the waste volume requiring disposal. While the gel formulation is suitable for cesium decontamination, it is not optimum for decontamination of actinides (e.g., americium), lanthanides, or fission products from porous surfaces, particularly concrete, brick, tile, marble, granite, and asphalt.
Decontamination of radionuclide ions (e.g., actinides, lanthanides, and fission products) from porous surfaces (e.g., concrete, brick, tile, marble, granite, asphalt, and the like) is generally very difficult because the porosity of the surface allows for penetration of the radionuclide ions below the surface of the material. In fact, there are very few non-destructive options for removal of actinide and other fission product ion contaminants from concrete, brick, tile, marble, granite, asphalt, and other porous surfaces. Most known decontamination protocols for actinide and other fission product ions are designed for decontamination of non-porous surfaces, such as metals. These protocols generally involve the use of harsh acids to remove the oxide scales that host the radionuclide ions. Acidic materials are destructive to many porous construction materials, such as concrete, brick, marble, and brick. In addition, strongly acidic materials are toxic, requiring deployment only in closed or contained environments.
There is an ongoing need for new, more efficient, non-destructive decontamination compositions and methods for removing actinide and lanthanide ions from porous surfaces. The present invention addresses this ongoing need.